rfkill & Bluetooth

I recently installed tlp on my Ubuntu XPS 13. One of tlp's features is restoring the radio device state on startup - eg disable bluetooth if bluetooth was disabled last time the computer was on. However, it doesn't work on my XPS. The people/person at linrunner walked me through troubleshooting the issue and concluded that the XPS13 uses hci0 for the bluetooth device which is "a kind of bogus device that doesn't really shut off the bluetooth hardware. This is the reason why TLP refuses to switch off bluetooth because it intentionally skips 'hci0'". Link to issue on github. I was also pointed to this patch, which suggests the dell laptop driver has dropped rfkill support.

Bluetooth drains battery, especially when it is not connected to anything. The kind folks at tlp suggested I add rfkill block bluetooth to a startup script, but seeing as it doesn't actually disable the hardware it sounds purely cosmetic.